1997+ Jeep Cherokee - Heat and AC Blend Door Replacement Parts
This is a new product developed by the HeaterTreater
Engineers for the common blend door failure problem on 97+ Jeep Cherokee.
Please check our feedback to get an idea of the product line integrity and
customer reaction to our products. We are committed to customer satisfaction
and successful repairs of blend door problems.
This is a kit
to do a complete repair on the blend door malfunction that is common to the 97-
01 Jeep Cherokee. Every Cherokee in this range either has, or will
have, this common failure. The pictures show the hardware provided for
the fix. All work is done from the foot area of the passenger side of the
Jeep, with a Dremel cut in the bottom of the heater box...no removal of the dash
panel or evacuating the AC system and draining the radiator. Once
completed, the alterations are under the dash panel in the foot area and are
not visible. The work to install the fix is relatively simple and can be
accomplished by the average shade tree mechanic. The work could easily be done
by any local independent garage. Product returns are accepted within two weeks
for a full refund(minus shipping).
The standard
fix for the blend door failure is to remove the heater box and replace the
plastic door. If the instructions with other fixes start out with “remove the
heater box”, be ready for considerable work. Removal of the box requires
removing the dash panel, evacuating and disconnecting the AC compressor,
draining and disconnecting the heater hoses. Fixing the door is relatively
easy, but the labor(and cost) of getting to the door makes this a time
consuming and expensive job. The HeaterTreaterTM avoids the hard work by
providing a kit that allows the repair to be done with superior components
without having to disassemble the automobile. 1hr work vs 8-14 hours of work,
and no specialized mechanical skills required.
The Problem:
-
The Cherokee is built with a Blend Door to control the heater and AC
function. The blend door controls air flow through either the AC
evaporator or the heater coil, or any combination in between. The doors
are controlled by a stepper motor. The issue with the system is that the drive
motor has a wider range of motion than the movement of the door will
allow. At the extents of movement(full heat or full AC), the motor
overdrives the plastic blend door into the the internal stop point in the
heater box until the motor stalls. This is considerable force on the door
and over time, the door cannot withstand the force and will break. Once
the door breaks, you lose control over the ability to regulate between heat and
AC.
- The standard factory fix is to replace the plastic door. The
process entails removing the heater box which requires - removing steering
wheel and steering column, removing radio and all dash panel control modules,
unbolting all attachment points for the dash panel, evacuating and
disconnecting the AC compressor, draining and disconnecting the radiator,
removing engine side bolts that hold the heater box in place. Once the
box is removed, the fix is relatively simple, but you still have cheap plastic
doors and the problem will occur again. It is not a particularly
difficult fix for an experienced technician, but it is an 8-12hr job plus refrigerant
and anti-freeze and the costs of labor and supplies adds up quickly into the
$800-$1200 range.
Do you have the problem?
The usual
symptom is an inability to effectively control the temperature of the HVAC
system. The door hangs on a vertical axis, so turning a sharp corner, or
fiddling with the fan speed can swing the door into the hot or cold position
randomly. While the symptoms are fairly conclusive for blend door failure, the
only way to really check it out is to remove the blend door actuator motor and look
at the axle.
The blend door
actuator motor is located in the upper left hand corner of the passenger side
foot well. The picture below show the location of the motor. The
motor is attached with three 5/16"(or 8mm) screws that can be easily
accessed and removed. Once you have detached the motor, you can turn the
HVAC system on and observe the movement of the motor by turning the temp
control knob. You want to make sure that the motor is moving
properly. (if the motor is broken, we can help with a replacement).
The motor attaches to the blend door using two different connector schemes
depending on the model year as shown in the second picture. You can grasp
the axle with your fingers and feel the extents of movement of the door by
turning the knob. You should be able to manually regulate between heat
and AC by turning the axle. The door should hit a hard stop point when
you turn it to heat or AC and not have any play beyond that point. If the
axle is broken or feel disconnected from the door, this is a definitive
indication of a broken blend door. It's hard to explain exactly what it
feels like, but you should be able to switch from AC to heat and feel a solid
stop at the max AC and heat positions. If the system is loose or ineffective,
the blend door is the problem and the HeaterTreater is the solution.
The HeaterTreaterTM
Solution:
This kit
replaces the plastic door and axle with stainless steel components that can
withstand the force and will last longer than the Cherokee. All work is done
from the passenger side foot well, and no disassembly of the dash or evacuation
of the AC system is required. Tools required are a screw driver, pair of
pliers, and a Dremel tool(if you don't already have one, this is a good
excuse and the tool has many uses. The area under the dash is confined and you
will need either a stubby Dremel tool(~6” long), or a flexible extension for a
larger industrial rotary tool. My favorite tool for the work is a Harbor
Freight mini benchtop grinder with a flexible rotary cutter attachment. #43533.
This setup has vaiable speed for the Dremel bits and is a good little bench
grinder for fine metal and polishing work. ). Dremel bits, and all hardware is
provided.
The repair will take about an hour the first time, and once you have
experience, about 45min. No extensive mechanical skills are
required. The picture shows the metal replacement kit. The plastic
door is accessed by using the Dremel tool and bit to cut into the plastic
heater housing from the bottom. Complete diagrams for the cutting pattern
are provided. It's a very simple process. The broken plastic door
is removed and replaced with the HeaterTreaterTM.
The instructions are written with multiple pictures and dual level
instructions. You can read the bold print only for experienced mechanics
or read the bold and standard for full "instructions for
Dummies". The instructions are almost insultingly simplistic for
those who care to read the entire document without admitting that they did it.
The fix is really easy and MUCH preferable to disassembly of the entire dash
and engine cooling systems. We provide support via email or phone if required.
Our goal is to make sure that every installation is successful. To date we have
achieved that goal and have no intention of letting up. This will solve the
problems with the blend door and is over-engineered to outlast the Wrangler.
Patent
Pending
